Capítulo quinto. Discusión

To explore the robustness of the previous results, Table 2.10 illustrates the results from estimating equations (2.6) and (2.7) using a random effects estimator that treats

42

The results are available upon request. 43

For robustness, this analysis has been replicated using a binary variable indicating whether the individual was bullied at age 7. The findings indicate that being bullied at age 7 is inversely associated with both measures of SWB. Predominantly, the estimates are statistically significant at the 5% significance level and are consistently statistically significant at the 10% level. However, the coefficients are smaller in magnitude, ranging from 30% to 70% of the magnitude of the coefficients relating to the effects of being bullied at age 11. These results are summarised in Tables 2.8 and 2.9.

40 the life satisfaction measure as if it were continuous. Table 2.10 is presented in an identical manner to Table 2.6(a).

Column (1) indicates that holding the adult characteristics and Mundlak averages constant, individuals who were bullied at age 11 report 0.161 points lower life satisfaction, relative to individuals who were never bullied. This effect is approximately 40% of the magnitude of the estimated effect of being unemployed on life satisfaction, or approximately 30% of the (absolute) magnitude of the effect of being married or cohabiting. Stutzer and Frey (2006) find that happier single individuals are more likely to marry in the future. If this selection effect is present in the NCDS data, the estimated effect of being married/ cohabiting on life satisfaction may be overestimated. Thus, arguably the findings presented in Table 2.10 may underestimate the true ratio of the effect of bullying on life satisfaction to the effect of marriage. Column (2) includes the childhood characteristics as control variables, reducing the magnitude of the estimated effect of being bullied by approximately a tenth, to -0.147. This indicates that birth-weight and mental health problems at age 7 are confounding variables. The use of Sample 2 increases the magnitude of the estimated effects of being bullied by approximately 10%. This may be because the more severely an individual was bullied at age 11, the greater their likelihood of absence from Sample 1.

41 Another notable feature of Table 2.10 is how the effect of the type of housing tenure varies from Sample 1 to Sample 2. In Sample 1, the estimated effects of being a private renter (relative to living in "social or other housing") are statistically insignificant. In contrast, in Sample 2, the estimated effects are negative and statistically significant at the 5% level. In Sample 1 and Sample 2 there are 948 and 1,989 renters, respectively. Thus, the differences in the estimated effects of renting on life satisfaction may be due to differences in the number of renters between the samples.

A similar pattern exists for the "owns home outright" variable. The analysis using Sample 1 demonstrates no significant effect of outright homeownership on life satisfaction, relative to living in "social/ other housing". However, the findings for Sample 2 demonstrate negative effects of outright homeownership on life satisfaction; these effects are significant at the 5% level. The results using Sample 1 also demonstrate small, negative effects of being male, relative to female, on life satisfaction. These effects are significant at the 10% level. In Sample 2, these coefficients are larger in magnitude and statistically significant at the 1% level. This may be because the least happy males are more likely to drop out of Sample 2.

Making use of Sample 1, the estimated effect of mental health problems (measured using the BSAG) at age 7 on life satisfaction is negative and statistically significant at the 5% level. This indicates that individuals with more mental health problems at age 7 report lower life satisfaction as adults. Thus, a one standard deviation increase in age 7 mental health problems reduces life satisfaction by approximately 0.05 points, a small effect. These results contrast with the findings using Sample 2, which show no statistically significant effect of mental health problems at age 7 on adult life satisfaction. A possible explanation for the inconsistent effect is that in Sample 2, mental health problems may be positively correlated with other characteristics that increase life satisfaction, such as low expectations.

Table 2.11 replicates the analysis of Table 2.10 using total malaise as the dependent variable. Columns (1) and (3) present the results from estimating equation (2.6) using Sample 3 (the total malaise balanced panel) and Sample 4 (the total malaise unbalanced panel), respectively. Columns (2) and (4) reveal the findings from estimating equation (2.7) using Sample 3 and Sample 4, respectively. Note that higher total malaise scores indicate higher SWB. In common with the life satisfaction results presented in Table 2.10, each specification is characterised by large, negative effects of being bullied at age 11 on SWB, as measured by total malaise. In all specifications, the estimated effects of being bullied are statistically significant at the 1% level.

The findings given in column (1) indicate that, conditioning on the adult characteristics and Mundlak averages, individuals who were bullied at age 11 have 0.193 points lower total malaise, relative to individuals who were never bullied. Column (2) includes birth-weight and mental health problems as control variables, reducing the magnitude of the estimated effect of being bullied by approximately 7%. Also, note that for both

42 outcome measures, the estimated effects of bullying victimisation on SWB are larger for the unbalanced panel, relative to the balanced panel, which may be due to non- response.

However, note that Table 2.11 presents some results that do not accord with the existing literature. For example, there is no statistically significant effect of marriage or cohabiting on total malaise, which may be due to adaptation to marriage, as found by Lucas and Clark (2006). The estimated effects of being registered disabled on total malaise are positive and statistically significant at the 1% significance level. Oswald and Powdthavee (2008) suggest that having health problems which limit an individual’s daily activities has a negative effect on mental distress and life satisfaction. One explanation for the difference between our results and theirs is that people who are registered as disabled may not be more likely to have health problems that limit their daily activities, relative to people who are not registered as disabled.44

Similarly, the estimated effects of monthly household income on total malaise are found to be negative, contrary to the conclusions of the existing SWB literature, see Frijters et al. (2004). This may be due to collinearity between monthly household income, highest educational attainment, and the homeownership status variables. However, re-estimation of the results without controlling for homeownership status leads to little change in the estimated effects of monthly household income on total malaise.